This invention is directed to an apparatus and method for sealing the fin of a gable-top carton. More specifically, the invention pertains to a top sealer jaw assembly for sealing and creasing the gable panels and fin of a gable top carton, and a method therefor.
Gable top cartons are in widespread use. Such cartons have been known for most of the twentieth century. The characteristic simplicity and widespread acceptance have helped to maintain their popularity as cartons for traditional products, such as liquid food products, for example, milk and juice.
In the early, tradition gable top carton, access to the contained product was facilitated by opening a portion or one side of the gable so as to form a spout from the carton material. While this configuration was and still is widely accepted, one drawback is that resealability of the carton is limited. That is, while the gable can be xe2x80x9crefoldedxe2x80x9d to close the carton, actual sealing (to reduce exposure to the environment, e.g., oxygen), is quite limited. To this end, improvements to such gable top cartons are ongoing.
In once such improvement, access to the product is provided by a spout that is integrally sealed to one of the gable panels. In a xe2x80x9cconventionalxe2x80x9d spout arrangement, an opening is formed in the gable panel and a plastic or like spout is welded or sealed to the panel. A cap, such as a threaded closure is fitted onto the spout to provide resealability of the container. Such spouts have come into widespread use and acceptance for their ease of access to the product and their ability to help maintain product freshness.
In still further enhancements to the gable top cartons, it has been found that it is desirable to provide an extended gable or top panel to permit the use of larger spouts. This is particularly true for more viscous or solids-containing products. Due to the nature of these extended top panels, it has been found that the typical forming and sealing arrangements for creasing and forming the top fin and the extended gable panel do produce the desired configuration vis-à-vis fin angles and creases.
Accordingly, there exists a need for improved top sealer configurations for use with gable top carton designs. Desirably, such top sealer enhancements permit the forming of high quality gable top carton fin or top panel seals. Most desirably, such top sealer enhancements further provide well defined creases and folds for these novel extended panel configurations.
A top sealer for a form, fill and seal packaging machine for forming, filling and sealing a gable top carton provides a top seal portion and a clean, distinct crease at the vertical panel/gable panel juncture. The packaging machine defines a processing path along which the cartons are conveyed. The top sealer is disposed after a filling station along the machine processing path.
The gable top cartons include a vertical panel (e.g., a front wall panel) and at least one gable panel contiguous with the vertical panel. The panels define a vertical panel/gable panel juncture. The cartons further include top fins that define a top seal portion of the carton. In one arrangement, the cartons include an extended gable panel and a shorter, secondary gable panel.
The sealer includes first and second anvils disposed on opposing sides of the processing path. The anvils are configured to move transverse to the processing path to engage the top fins and compress the fins to form the top seal.
A wedge is mounted to at least one anvil, and preferably to both anvils. One of the wedges has one or more raised portions extending from a face of the wedge. The wedge is mounted to the anvil so that the raised portions contact the vertical panel/gable panel juncture contemporaneous with the anvils engaging the top fins. Contact of the raised portion with the vertical panel/gable panel juncture forms a clean, distinct crease at the juncture.
In one embodiment, the wedge defines a face having a planar portion or face and the raised portion extends from the planar face. The top sealer can include a plurality of wedges mounted to one of the anvils. In this configuration, some of the wedges can include raised portions and others of the wedges can include only planar face portions. Preferably, about one-half of the wedges include raised portions.
A method for forming a top seal on a gable top carton and for creasing a gable panel/vertical panel juncture includes providing first and second anvils disposed on opposing sides of the processing path, mounting a first wedge section to the first anvil and mounting a second wedge section to the second anvil. The first wedge section includes at least one wedge having a raised portion extending from a face of the wedge.
The method further includes transversely moving the anvils toward one another to engage the top fin panels of the carton and to compress the fins for forming the top seal portion of the carton. Contemporaneous with engaging the top fins, the method includes contacting the first wedge raised portion to the vertical panel/gable panel juncture to form a crease at that juncture.
In a preferred method, the anvils and wedges engage the top fin panels at least twice. Most preferably, the first wedge section raised portion contacts the carton at the vertical panel/gable panel juncture in a second or subsequent engagement of the anvils with the top fin panels.
These and other features and advantages of the present invention will be apparent from the following detailed description, the accompanying drawings, and the appended claims.